Cooled x-ray tube head

ABSTRACT

577,081. R÷ntgenray apparatus. GOLDFIELD, E. R., and GRAVES, E. B. Feb. 17, 1944, No. 2983. [Class 98 (i)] [Also in Group XL] An X-ray tube is immersed in liquid in a casing of heat-conducting material over the surface of which air is passed by a fan in an outer housing, the casing having a removable cover accessible after removal of a cover of the outer housing, both covers being spaced from each other and forming portions of the walls of the air current path. In the form shown, two fans 31 blow external air upwards between the inner casing 10 containing the X-ray tube 13 and transformer 14 and the left-hand side of the housing 19, between the two covers 11, 22 and downwards over the right-hand side of casing 10. A motor-driven impeller 15 circulates the oil in the casing 10 which has bellows 17, 18 to permit expansion of the oil.

y 1944- E. R. GbLDFlELD ET AL 2,353,720

COOLED X-RAY TUBE HEAD Filed Feb. 23, 1942 2 Sheets-Sheet l 4 v 92 IQb FIG-l I l I FIG-3 ii lNVENTORS I90 7 19b EDWIN R. GOLDFIELD E DVARD B. GRAVES ATTORNEYS y 1944. E, R. GOLDFIELD ET AL 2,353,720

COOLED X-RAY TUBE HEAD Filed Feb. 23, 1942 2 Sheets-Sheet 2 M EE E r u MHN W F E R Mo Nw T l B A R D N IMM MD EE IOb nections need no illustration here.

Patented July 18, 1944 UNITED STATES PATENT OFFICE GOOLED X-RAY TUBE HEAD poration of Ohio Application February 23, 1942, Serial No. 431,922

7 Claims.

This invention relates to improvements in the cooling of X-ray tube heads and provides means whereby X-ray tubes may be used continuously for long periods of time.

One of the objects of the present invention is to provide a very compact tube head with the cooling apparatus built into the tube housing structure so that the entire equipment occupies very small space and yet provides a very efficient cooling system.

Another object of the present invention is to combine an X-ray tube and its associated transformer equipment in a single compact cooling system.

Other objects and advantages include the detailed arrangement of the air blowing means and partition means in the housing, the formation of the housing cover to provide part of the cooling system, and the provision of novel means for supporting the entire tube head and housing. All of these will be apparent from the accompanying drawings and description and the essential features will be set forth in the claims.

In the drawings, Fig. 1 is an end elevational view of our improved tube head; Fig. 2 is a side elevation thereof; Fig. 3 is a transverse sectional view taken approximately on the line 33 of Fig. 4; Fig. 4 is a view partly in end elevation and partly in section taken along the line 44 of Fig. 2; Fig. 5 is a top plan View of an interior casing taken along the line 55 of Fig. 4; while Fig. 6 is a fragmental sectional view taken approximately along the line 6-6 of Fig. 3.

One of the problems encountered in continuous operation of X-ray tubes is the dissipation of heat both from the tube and the transformer. Heretofore cumbersome equipment has been utilized to dissipate this heat but our present invention provides a very efiicient means for this purpose concentrated in such a small space that the equipment may be used where great portability is desired, such as, for instance, the use of X-ray equipment with an army in the field.

Referring to Fig. 4, an inside liquid-tight casing I0 is provided extending from end to end of the head. This casing has a removable cover H attached by securing members l2 and provided with suitable gasket means so that no liquid can escape from the casing. Within the casing is mounted an X-ray tube l3 and a transformer I4 of a usual type provided with taps for filament current, and other taps for tube current in the usual well known manner. Such con- The casing I 0 is filled with a heat conducting electrical insudrical bottom wall l9a.

lating liquid, such as one of the oils commonly used for this purpose. Within the casing and submerged in the oil thereof is an impeller 15 driven by a motor it. This impeller I5 is preferably approximately opposite the target of the tube but not necessarily so. When the tube and transformer are in operation, the motor I6 is running and the impeller I5 keeps the oil in the casing 10 in circulation. This transfers heat from the tube and the transformer to the walls of the casing In. These walls are of a heat conducting material and readily dissipate the heat to the outer surfaceof the casing. Means is provided as hereinafter disclosed for causing a stream of air to pass continuously over the outer surface of the casing l0 so as to carry away the heat from that point.

Commmiicating with the interior of the casing ID are expansion bellows housed in the projections I! and l8. These are of the usual type to take care of expansion and contraction of the liquid in the casing l0 under varying heat conditions. One of these bellows may be equipped with a safety switch for preventing overheating of the tube such as is disclosed in the copending application of Edwin R. Goldfield, Serial No. 358,602, filed September 27, 1940.

An outer housing l9 has side walls as best seen in Fig. 4, generally parellel to and spaced from the side walls of the casing I0, thus providing air passageways along both sides of the casing. The housing has a perforated semicylin- The housing is completed by the end walls, l9b which are imperforate except for openings I90, the purpose of which will later appear. The side walls of the housing are cut away as shown at I9d, Fig. 2, so that the projections I1 and I8 may enter into the cut-away portion of the housing, after which plates 20 on each side are secured in place by screws 2|, thus fixing the position of the housing [9 outside of the casing l0. A removable cover 22 is provided for the housing l9 overlapping the side walls thereof at 22a when the cover is in place. There is thus provided a continuous pasprovides access to the top cover of the casing 10 which is shown at H in Fig. 5. This top cover carries the binding posts for the connections leading. to the various electrical equipment within the casing ID. The binding posts 23 are for the motor IS, The binding posts 24 lead tube or. the. transformer.

to the safety switch previously referred to as housed in one of the projections H or l8. The binding posts 25 are for the filament transformer, and the binding posts 26 are for the main transformer connections. The opening Hlb is for the emission of X-rays and is closed by'a plastic window.

Mounted 'in the cover 22 are the diaphragm shutters 21 for controlling the X-rays from the tube I3. The position of the shutters is controlled by the rod 28 which extends through a suitable opening in the cover. Further description of these shutter diaphragms is unnecessary as they are similar to thos'e'disclosed in the copending application of 'Goldfield, Schiring and Stava, Serial No. 386,390, filed April 2, 1941. This shutter equipment is affixed to the bosses 29 in the cover.

When in use, the usual cone sets in the depression 22b and the opening in the top of the cover is closed sufficiently airtight by an aluminum filter 22c about mm. thick or by a plastic sheet of equivalent X-ray filtration.

Means for circulating theair is provided withinthe housing 19 and closely adjacent to one wall of the casing [0 so as to provide a very compactequipment. As hereshown this blower means is beneath the casing H) and within the semicylindrical portion l9a of the housing, thus giving a'very pleasing appearance to the complete head. A-motor '30 is suitably supported in the mid portion of the housing and has its drive shaft- 30a extending toward each end of the -housing.- Mounted on each shaft is an impeller 3] blades separated by the partition 31a. Around the impeller is the usual involute housing 32 which lies against the inner face of the housing at 32a, thus closing oifthe perforations in the bottom-ofthe-housing and giving a closed conduit for air-up to the point 322) wherethe air is discharged from the blower into the passageway between thecasing l0 and the housing 19. Thus air will enter at the center of the impellers 3| and be discharged'at 32b-to follow the arrows around three sides of the casing ill and being discharged through the perforations we at the outlet side of the housing. To insure that warm air at the outlet is not drawn into the impellers, a partition plate 33 extends between the impeller housings 32 at the right-hand side of the motor 30 as seen in Figs. -3 and 4. Air enters the impellers. through the openings I90 in the ends of the'housing l9. Air mayalso enter at the annular openings 32c around the shafts 30a. Because of i the partition 33 this inlet air must come through the perforations 19f at the lefthand side of the housing [9 as viewed in Figs. 3 and 4.

The tube headmay besupported from a suitableutube stand in any desired manner but as here shown supporting arms 34 are indicated engaging .the projections H and I8.

It will thus be seen that we have provided a very compact and eflicient cooling means for an X-ray tube and transformer, all contained withina single housing of very pleasing appearance and. occupying very little space. This equipment therefore is easily carried with an army inthe fieldand can be operated for long periods continuously without danger of overheating the The overall dimensions .of. thehead inside the Sylphon housings 1 and L8 are 7 /2 inches wide,- 10%; inches long and 13 A2, inches high.

preferably having a double set of What we claim is:

1. An X-ray tube head comprising a liquidtight casing of heat conducting material, an X- ray tube in said casing, heat conducting electrical insulating oil in said casing surrounding said tube, means for agitating said oil, a housing spaced from the outside of said casing and providing a passageway around said casing, blower means positioned in said housing and below said casing, and partition means for causing a stream of air from said blower means to traverse said passageway up one side of said casing, across the top thereof and down the other side of said casing.

2. An X-ray tube head comprising a liquidtight casing of heat conducting material, an X- ray tube in said casing, heat conducting electrical insulating oil in said casing surrounding said tube, means for agitating said oil, a housing spaced from the outside of said casing and providing a passageway around said casing, blower means positioned in saidhousing and below said casing and including a rotatable impeller and a rounded casing therefor, said housing having a bottom wall mergingv with and generally following said rounded impeller casing, and partition means for causing a stream of air fromsaid blower means to traverse said passageway up one side of said first named casing, across the top thereof and down the other side of said first named casing.

3. An X-ray tube head comprising a liquidtight casing of heat conducting material, an X-ray tube in said casing, heat conducting electrical insulating oil in said casing surrounding said tube, means for agitating said oil, a housing spaced from the outside of said casing and providing a passageway around said casing, blower means positioned in said housing and. below said casing and including a rotatable impeller and a rounded casing therefor, said housing having a perforate bottom wall merging with and generally following said rounded impeller casing, and partition means for causing a stream of air impelled by said blower means to enter said perforate bottom wall at one side thereof, to traverse said passageway up one side of said first named casing, across the top thereof, down the other side of said first named casing and out of said perforate bottom wall at the other side thereof.

4. An X-ray tube head comprising a liquidtight casing of heat conducting material, an X-ray tube in said casing, heat conducting electrical insulating oil in said casing surrounding said tube, means for agitating said oil, a housing spaced from the outside of said casing and providing a passageway around said casing, blower means positioned in said housing and below said casing and including two rotatable impellers and a motor between them having driving connections with them, each impeller having arounded casing, said housing having a perforate bottom wall merging with and generally following said rounded impeller casing, and partition means for causing a stream of air impelled bysaid blower means to enter said bottom wall and pass around said casing in said passageway and thence pass out through said bottom wall.

5. An X-ray tub head comprising a liquidtight casing of heat conducting material, an X-ray tube in said casing, heat conducting electrical insulating oil in said casing surrounding said tube, means for agitating said oil, a housing spaced from the outside of said casing and providing a passageway around said casing, blower means positioned in said housing and below said casing and including two rotatable impellers and a motor between them having a driving shaft connected with them, each impeller having a casing arranged to discharge air upwardly along one side of said first named casing, said housing having a perforate bottom wall in the central zone opposite said motor, there being openings through each impeller casing positioned axially of the impeller and on opposite sides thereof, and partition means in said central zone of the bottom portion of said housing between said impeller casings, whereby air from one side of the bottom portion of said housing enters centrally of each impeller at opposite sides thereof and then passes around three sides of said first named casing and out at the other side of the bottom portion of said housing.

6. An X-ray tube head comprising a liquidtight casing of heat conducting material, an X-ray tube in said casing, heat conducting electrical insulating oil in said casing surrounding said tube, means for agitating said oil, a housing spaced from the outside of said casing and providing a passageway around said casing, blower means positioned adjacent said passageway for causing a flow of air therethrough, said housing including a cover removable for access to said casing, said casing carrying electrical connections for said tube accessible upon removal of said cover, and said cover when-in place providing a wall of said passageway.

7. An X-ray tube head comprising a liquidtight casing of heat conducting material, an X-ray tube in said casing, a cover for said casing providing access to the interior thereof, heat conducting electrical insulating oil in said casing surrounding said tube, means for agitating said oil, a housing spaced from the outside of said casing and providing a passageway around said casing, blower means positioned adjacent said passageway for causing a flow of air therethrough,

I said housing including a cover adjacent said casing cover and removable for access to said casing, there being aligned X-ray pervious partitrons in said casing and housing covers for pasproviding walls of said passageway.

EDWIN R. GOLDFIELD. EDWARD B. GRAVES. 

